Dean Norris as James “Big Jim” Rennie, left, Alexander Koch as Junior Rennie, Natalie Martinez as Linda Esquivel and Mike Vogel as Dale “Barbie” Barbara in “Under the Dome,” which started its second season June 30. (CBS)

Their characters may be trapped “Under the Dome” in Chester’s Mill, but the hit CBS show’s actors are willingly entering a bubble of another sort in San Diego: Comic-Con International’s Ballroom 20.

Big Jim himself — Dean Norris — and cast mates Mike Vogel (military veteran Dale ‘Barbie’ Barbara), Rachelle Lefevre (reporter Julia Shumway), Alexander Koch (the troubled Junior “My Name Is James” Rennie), Colin Ford (separated-from-his-family teen Joe McAlister) and Eddie Cahill (Big Jim’s brother-in-law Sam Verdreaux) will join executive producer Neal Baer to kick off CBS Television Studios’ consecutive panels on July 24 at 11:15 a.m. in the large-capacity room. The presentation also includes a premiere screening and panel for the new CBS drama “Scorpion” at 12:15 p.m. and a sneak preview of the second season of the CW historical drama “Reign” at 1:15 p.m., ending at 2 p.m.

“Under the Dome,” based on the Stephen King novel of the same name and developed for television by Brian K. Vaughan (TV’s “Lost,” comics’ “Saga”), started its second season June 30. The panel will feature a sneak peek at what’s coming up.

Real-life genius Walter O’Brien is the inspiration for “Scorpion,” which shares a name with his hacker alias and computer services company, and is about him and a team of fellow bright outcasts working to keep the nation safe from high-tech dangers (and learning to live together, of course).

He’ll be on hand along with cast members Elyes Gabel (“World War Z,” “Body of Proof”) , who stars as him, Katharine McPhee (“Smash,” “American Idol”) and Robert Patrick (“Terminator 2,” late-seasons “X-Files”) to talk after the premiere screening. Executive producers Nick Santora (“Prison Break”), Nicholas Wootton (“NYPD Blue”), Justin Lin (“Fast & Furious” films) and Alex Kurtzman and Roberto Orci (who’ve teamed on “Fringe,” “Star Trek” films and more) will also speak on the panel. The series will join the CBS lineup this fall.